Here are a few reasons why a radio station submitted is rejected with stream url :-

Invalid URL - This could be that the URL is incorrectly written or you are using a URL that points to a web page or web player.Inactive URL - Your stream musn't be active 24 hours each day. But stream url active must be 7 days from since submission date.We must know the following:​​Streaming bitrateStreaming format (mp3, aac, etc.)We recommend testing the URL in a media player like VLC or WinAmp. In most but not all cases, if the URL is working in either of these media players, it will be playable using Listen Online Radio.